vfs: make do_kern_mount() static

the only user outside of fs/namespace.c has died
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/namespace.c

@@ -1929,7 +1929,7 @@ static struct vfsmount *fs_set_subtype(struct vfsmount *mnt, const char *fstype)
 	return ERR_PTR(err);
 }
 
-struct vfsmount *
+static struct vfsmount *
 do_kern_mount(const char *fstype, int flags, const char *name, void *data)
 {
 	struct file_system_type *type = get_fs_type(fstype);
@@ -1943,7 +1943,6 @@ do_kern_mount(const char *fstype, int flags, const char *name, void *data)
 	put_filesystem(type);
 	return mnt;
 }
-EXPORT_SYMBOL_GPL(do_kern_mount);
 
 /*
  * add a mount into a namespace's mount tree

include/linux/mount.h

@@ -100,9 +100,6 @@ extern void mnt_pin(struct vfsmount *mnt);
 extern void mnt_unpin(struct vfsmount *mnt);
 extern int __mnt_is_readonly(struct vfsmount *mnt);
 
-extern struct vfsmount *do_kern_mount(const char *fstype, int flags,
-				      const char *name, void *data);
-
 struct file_system_type;
 extern struct vfsmount *vfs_kern_mount(struct file_system_type *type,
 				      int flags, const char *name,